Actuator system

ABSTRACT

An actuator system particularly suitable for quickly imparting motion to closure members or bodies of relatively large mass, wherein a reservoir of high pressure gas is provided adjacent a piston portion of the body to be moved so that rupture of the reservoir by a shaped charge of explosive rapidly releases the gas to thereby effect very rapid movement or velocity of the closure member or body.

United States Patent Howell et al. 51 Nov. 14, 1972 ACTUATOR SYSTEM H 156] References Cited [72] inventors: Harold D. Howell; Thomas O. UNn-EDSTATES PATENTS Hunter, both of Albuquerque;

Robert Sflnebwsh, e alta, all of 3,373,758 3/1968 Boutweli er al. um/oa N. Mex. 3,567,245 3/1971 Ekstrom ..l37/68 X Assignee: The United States of America as represented by the United States Atomic Energy Commission Filed: Aug. 10, 1971 Appl. No.: 170,438

US. Cl. .137/68, 60/26.l, 91/5,

251/64 Int. Cl. a ..Fl6k 31/12 Field of Search ..137l68; 91/5; 60/26.1

Primary Examiner-Robert G. Nilson Attorney-Roland A. Anderson ABSTRACT An actuator system particularly suitable for quickly imparting motion to closure members or bodies of relatively large mass, wherein a reservoir of high pressure gas is provided adjacent a piston portion of the body to be moved so that rupture of the reservoir by a shaped charge of explosive rapidly releases the gas to thereby efiect very rapid movement or velocity of the closure member or body.

PKTENTED 3.702.620

INVENTORS HAROLD o. HOWELL THOMAS o. HUNTER ROBERT .E. STINEBAUGH ACTUATOR SYSTEM BACKGROUND OF INVENTION This invention relates to an actuator system and more particularly to an actuator system which is especially advantageous for effecting the very rapid movement of bodies having a relatively large mass. The system of the invention is particularly useful for actuating valve gate mechanisms.

There are a number of applications which demand that a closure member or gate be moved some distance, such as across an opening of a valve or other feature, in a very short time and in a manner which is highly reliable. Applications of this type may be found in connection with the testing of nuclear explosives, sputtering gas pipe lines, closing oil pipe lines, etc. One application utilized to gain information regarding the characteristics of a nuclear explosive employs one or more pipes axially disposed with respect to the explosive to be detonated. Instruments to measure the radiation emitted upon detonation are spaced at a predetermined distance along one or more of the pipes. It is desirable to protect these instruments from debris and the shock front which follows the radiation front down the pipe at a very small time differential. At a distance of several hundred feet from the point of detonation, the period of time between passage of the radiation front and the arrival of debris and the shock front may be on the order of 50 milliseconds. A typical aperture that must be closed in this extremely short period of time is on the order 8 square feet, and the gate closing this aperture must, of course, be sturdy enough to withstand the debris and shock.

SUMMARY OF INVENTION Accordingly, it is an object of this invention to provide an actuating system for effecting very rapid movement of a body, and in particular a body of relatively large mass, in a highly reliable manner. Very briefly summarized, this and other objects of the invention are accomplished by providing a reservoir of high pressure gas between a piston portion of the body to be moved and an enclosed end of a chamber in which the body is positioned. Effecting release of high pressure gas from the reservoir causes the desired movement of the body away from the end of the chamber. The use of a shaped charge of explosive to rupture the reservoir container is a particularly advantageous means of releasing the gas thereby effecting movement of the body.

The objects and advantages of the invention will be more apparent after consideration of the following description of a preferred embodiment of the invention in a gate valve.

BRIEF DESCRIPTION OF DRAWING FIG. 1 is a partially broken away, separated, perspective view of an embodiment of the invention in a gate valve;

FIG. 2 is an enlarged, cross sectional view of the gate valve of FIG. 1; and

FIG. 3 is a fragmentary sectional view showing the relationship of certain elements shortly after actuation of the system.

DESCRIPTION OF A PREFERRED EMBODIMENT With specific reference to the drawing, an actuator system according to the invention is shown in an embodiment in a gate type valve 10. Valve 10 includes a housing or valve body 12 having appropriately shaped ports 14 and 16 and an elongated portion 18 with appropriate side and end walls, best shown in FIG. 2, in which a body or gate 20 of rectangular, cylindrical or other appropriate shape is positioned when valve 10 is open to permit passage of fluid, radiation, or the like through ports 14 and 16. The width and depth, size and shape of gate 20 may be complementary to the width and depth of the chamber formed by elongated portion 18 so that it essentially fills the chamber and yet is movable therewithin in longitudinal direction in any desired vertical, horizontal, or other orientation from an open position such as shown in FIG. 2 to a closed position, not shown, where it blocks ports 14 and 16. One or more of the ports 14 and 16 may be appropriately coupled to some desired conduit or passageway for conveyance of some fluid or material therethrough in a well known manner.

When top plate 22 in its assembled position as shown in FIG. 2, it encloses or covers the chamber formed by elongated portion 18 at its upper end. Positioned between the end of gate 20 and top plate 22 is a container or reservoir 24 which is adapted to hold a quantity of air or other gas under high pressure; while shown of generally cylindrical configuration, the reservoir may be of spherical or other suitable shape. Since gate 20 fills the chamber formed by elongated portion 18, it acts as a piston therein and will be driven downwardly to block ports 14 and 16 upon release of the high pressure gas from reservoir 24. The manner in which gate 20 is held in its open position and, in turn, released therefrom in conjunction with release of high pressure gas from reservoir 24 will now be explained.

The support of gate 20 in its open or upper most position, as shown in FIG. 2, may be obtained through bolts 26, support plate 28, U-clamps 30, bolts 32, container or reservoir 24, bolts 34, nuts 36 and top plate 22. Upper spacing plate 33, fastened to top plate 22 by bolts 35, while not participating in the support of gate 20 completes the enclosure of reservoir container 24. Other support arrangements may be used for gate 20, within the teachings of this invention depending on the size, shape and orientation of the valve and other requirements of these variations. The release of gate 20 from the linkage of support elements, as well as the release of the high pressure gas to provide the actuating force, is obtained by severing container 24, preferably through an equator or mid-portion thereof, by detonation of a shaped, linear explosive charge 40 by suitable means such as an electrical impulse delivered through cable 42. Until container 24 is severed, the gate supports need only hold the gate against gravity forces, if any, of the gate and other portions of the driven valve.

The use of a shaped charge for cutting pipes, plates, and various other items is well known. Preferably a shaped explosive charge, frequently encased in a metal sheath, is employed to form, upon detonation, a focused plasma of high temperature reaction products which melts or shocks through the item to be severed. Optimum spacing between the shaped explosive and the reservoir wall to be cut, known as the standoff distance," may be obtained by utilizing a metal or plastic channel member, such as standofi channel 44.

As shown in the drawing, linear charge 40 and standoff channel 44 encircle reservoir or container 24. For ease of assembly, and to prevent undesirable load being placed on charge 40 or channel 44, assembly support plate 46 is provided and standoff channel 44 is secured thereto by fastening means such as screws, not shown.

After the shaped charge 40 if fired and container 24 severed, such as about its periphery, the high pressure gas stored in container 24 may expand and drive gate 20 through the chamber in portion 18 of the housing across and blocking ports 14 and 16. Container 24 is effectively split into at least two portions 240 and 24b, one portion of which, portion 24b, is driven with gate 20 to effect closure, as shown in the somewhat simplified view of FIG. 3. Appropriate static or pressure actuated gaskets and seals (not shown) or the like may be interposed between gate 20 and the housing about ports 14 and 16 to effect a seal for blockage of fluids or gases, if such is desired.

In one application of a valve system generally in accordance with the foregoing, a valve gate having a width of about 58 in. and depth of about in. and weighing approximately 2,000 lbs. was driven across an opening measuring 24 inches by 52 inches in a time of only 12.8 milliseconds by the release of approximately 1,500 cu. in. of gas from a reservoir at about 5,000 psi. The high driving force (for this embodiment about 2,900,000 pounds of initial force) on the gate was delivered practically instantaneously (about 100 11. seconds after detonator firing) upon severing of the reservoir wall with less than 1 pound of explosive. Higher reservoir pressures and use of multiple detonators spaced about the shaped charge effect even greater gate velocities in shorter periods of time, much higher velocities in shorter time periods than would be furnished be merely firing a powder charge in the chamber.

In view of the large quantity of kinetic energy imparted to the gate by the high pressure gas, it is desirable that there be provided means for absorbing this energy and stopping the gate in a positive manner, without objectionable rebound. A very satisfactory means of accomplishing this is provided by the use of proportionately thin walled tubes 52 and tapered mandrels 54 which, after a short entry portion, having increasingly larger diameters than the interior diameters or cross sections of the tubes.

As each tube 52 is driven over its corresponding mandrel 54, the tube experiences a circumferential strain proportional to the increase in the diameter of the mandrel. The contact force between the mandrel and tube induces a frictional force which opposes the relative motion between them. This frictional force is a function of the tube material yield stress, the thickness of the tube, the area of contact between the mandrel and the tube and the coefficient of friction. The energy absorbed by each mandrel and tube combination is proportional to the product of the frictional force (above) and the distance traveled by the tube after initial contact with the mandrel. The system is selflatching since when motion is stopped, a force greater than or equal to the final force encountered is required to cause additional motion in either direction. The use of a crushable honeycomb material 56 surrounding mandrel 54 (or tube 52) has been found to effectively reduce the distance required for stopping the gate without affecting the self-latching feature of the tubemandrel arrangement.

The actuating system of the invention utilized in the gate valve according to the foregoing has proven to be exceedingly fast operating and reliable in moving a gate a desired distance. An important feature of the actuating system of the invention when used to operate valve gates is that containment of the high pressure gas is not dependent upon maintenance of seals between the gate and the valve body and that reliable, long term storage of energy in the form of high pressure gas may be achieved. This feature greatly simplifies valve construction and enhances the reliability of the valves. In order to unlatch the system and withdraw the gate 20 to an initial position top plate 22 and plate 33 may be removed and gate 20 lifted from its latched position by unbolting mandrels 54. After each use, replacement of the expended items, i.e., shaped charge 40, standoff channel 44, the high pressure gas and gas reservoir 24, tubes 52, mandrels 54 and honeycomb material 56 renders the valve ready for the next use. The manner in which access is gained to these items will be readily apparent from a perusal of the drawing.

Many alterations in the particular configuration of a valve utilizing the actuator system according to the invention will be apparent to those skilled in the art. For instance, it will be appreciated that the arrangement of the ports can be such that the movement of the gate opens, or successively opens and closes, the valve rather than merely closing the valve as described above. Also the closure time can be cut almost in half by providing two gates, as stated above, each moving across the aperture from an opposing direction. Moreover, it will be apparent that the actuating system of the invention is readily adaptable to many applications other than gate type valves, such as, for example, the controlled movement of any of many kinds of bodies. Accordingly, it will be understood that various changes in the details herein described and illustrated in order to explain the nature of the invention may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.

What is claimed is:

1. An actuator system comprising a housing having a conductive passageway therethrough, a movable closure member within said housing for controlling flow through said passageway, a high pressure gas reservoir carried by said housing adjacent the closure member, and means for effecting sudden release of gas from said reservoir and movement of said closure member including an explosive charge for rupturing a wall of said reservoir.

2. The system of claim 1 wherein said explosive charge is of linear configuration and extends along a wall portion of said reservoir.

3. The system of claim 2 wherein said charge is shaped to direct explosive energy toward said reservoir wall.

4. The system of claim 2 wherein said charge is disposed at essentially a median plane of said reservoir.

tube and tapered mandrel, wherein at least a portion of the tapered mandrel has increasingly larger diameters than said tube, one of said pair being carried by said closure member and the other being carried by said housing.

8. The system of claim 7 including a crushable honeycomb material adjacent at least one of said tube and mandrel. 

1. An actuator system comprising a housing having a conductive passageway therethrough, a movable closure member within said housing for controlling flow through said passageway, a high pressure gas reservoir carried by said housing adjacent the closure member, and means for effecting sudden release of gas from said reservoir and movement of said closure member including an explosive charge for rupturing a wall of said reservoir.
 2. The system of claim 1 wherein said explosive charge is of linear configuration and extends along a wall portion of said reservoir.
 3. The system of claim 2 wherein said charge is shaped to direct explosive energy toward said reservoir wall.
 4. The system of claim 2 wherein said charge is disposed at essentially a median plane of said reservoir.
 5. The system of claim 1 wherein said reservoir is secured at one portion to said closure member and at another portion to said housing, and said explosive charge is positioned to rupture the reservoir wall intermediate said secured portions.
 6. The system of claim 1 including means for stopping said closure member and retaining it against rebound.
 7. The system of claim 6 wherein said means for stopping comprise at least one pair of a complementary tube and tapered mandrel, wherein at least a portion of the tapered mandrel has increasingly larger diameters than said tube, one of said pair being carried by said closure member and the other being carried by said housing.
 8. The system of claim 7 including a crushable honeycomb material adjacent at least one of said tube and mandrel. 